Video Javascript SDK Release Notes

Fixed

• Fixed an issue where a black flicker could briefly appear on a subscribed stream immediately after subscribing during 1-on-1 calls on Safari.

• Fixed an issue where retrieving WebRTC statistics could throw a TypeError on iOS WKWebView and Capacitor-wrapped apps, causing errors when collecting stats or running network tests.

• Fixed an issue on Firefox where rapidly toggling video off and on (calling publishVideo(false) immediately followed by publishVideo(true)) could intermittently leave the published video disabled, showing a black frame until the next toggle.

• Fixed an issue where the audioLocalCandidateType, videoLocalCandidateType, audioRemoteCandidateType, and videoRemoteCandidateType fields in the QoS stats could report incorrect values by using the last ICE candidate instead of the selected one.

• Fixed an issue where a subscriber could fail to start when the browser's autoplay policy blocked video playback. The subscriber now times out the play attempt and continues with muted audio (which the user can unmute) instead of failing to subscribe.

• Improved the automatic reconnection logic so that the reconnection timeout window is no longer reset on every transport reconnection, preventing the client from getting stuck in an infinite reconnection cycle.

• Fixed an issue where video filters, background blur, and background replacement did not work on Safari 27 and iOS 27.

Added

• Promise support for async SDK methods (non-breaking). The JS SDK now supports modern async/await and promise-based patterns alongside the existing callback-based API. This change is fully backward compatible — all existing callback-based code continues to work without modification. As part of this work, the SDK gained finer control over errors in its internal flows and now surfaces error information more accurately. Starting with version 2.35.1, some functions report errors that were previously silent. These are not new failures — they are pre-existing errors that are now correctly propagated, so you may observe errors being reported in cases that previously went unnoticed. For more information, see this documentation.

• Scalability Mode API. This version adds a new API that allows publishers to explicitly set the target scalability mode, giving developers fine-grained control over the number of spatial (resolution) and temporal (frame rate) layers used during encoding. This enables applications to better balance video quality, adaptability, and resource usage based on their specific needs. For more information, see this documentation. This is a beta feature.

• Performed Android 17 validation. The Vonage Web SDK has been validated on Android 17, confirming smooth operation across Android mobile browsers and WebView applications.

Fixed

• Fixed an issue where, in some cases, subscribing to a VP9 stream failed when the publisher had set videoContentHint to "detail" or "text".

• Fixed a memory leak in audio processing across subscribe/unsubscribe and publish/unpublish cycles that in some cases could lead to unbounded heap growth and audio degradation over time.

• Fixed an issue where in some cases retrying to publish after a failed attempt resulted in a false positive, causing the session.publish callback to report success when the publish had not actually succeeded.

• Fixed an issue where in some cases relay ICE candidates were not included when establishing a connection, which could result in connectivity failures in networks that require TURN relay.

• Fixed an issue where in some cases applying or clearing a video filter after changing the publisher's resolution produced an unexpected zoom effect.

• Fixed an issue where OT.hasMediaProcessorSupport() incorrectly returned false on iOS 26 WKWebView due to Apple's frozen user agent string, blocking the use of Publisher.applyVideoFilter() on affected devices. Additionally, a new asynchronous variant OT.hasMediaProcessorSupport.promise() has been added, which performs a more thorough check of the browser's capabilities and is recommended over the static version for a more accurate and future-proof result.

• Fixed an issue where end-to-end encryption did not work on Safari when the developer tools were opened.

• Fixed an issue introduced in version 2.34.0 where applications enforcing a strict Content Security Policy (CSP) could experience violations when using background blur or background replacement on Safari and Firefox, due to the use of an inline web worker. The inline web worker has been removed, eliminating these CSP violations.

• Fixed an issue in the JS SDK where calling publishVideo(false) after setPreferredResolution() or setPreferredFrameRate() would incorrectly return a constraint error on Firefox and Safari.

Fixed

• Fixed an issue where switching audio input devices (for example, connecting Bluetooth headphones) shortly after session start could trigger an audioAcquisitionProblem that caused complete audio loss for remote participants once the session transitioned to a routed topology.

• Fixed an issue where applications running inside an Android Chrome WebView could not access the precall test or join a video conference.

• Fixed a missing TypeScript definition: the constraints property was not included in the GetUserMediaProperties interface in ot.d.ts, causing a mismatch with the actual runtime behaviour of the SDK.

Fixed

• Fixed an issue where using publisher.setPreferredResolution() in combination with a background filter (blur or replacement) caused the published resolution to change to an unexpected value. The publisher now maintains the intended resolution when a background filter is applied.

• Fixed an issue where toggling video off and back on (publishVideo(false) followed by publishVideo(true)) while a background filter (blur or replacement) was active could briefly expose unfiltered frames to remote participants. The SDK now ensures only filtered frames are sent after video is re-enabled.

• Fixed a change introduced in v2.34 where the TypeScript definition of OT.hasMediaProcessorSupport() incorrectly required a mediaType parameter. The mediaType parameter is now optional, restoring compatibility with existing code that calls OT.hasMediaProcessorSupport() without arguments.

Added

• Added new network condition insights. This version adds new network condition metrics to the client observability feature, providing detailed visibility into network performance and quality indicators. These metrics complement the publisher and subscriber statistics introduced in 2.33.0 and help developers proactively monitor network conditions affecting video quality, diagnose connectivity issues, and make informed decisions about potential adjustments. For more information, see this documentation.

• Added support for background blur and background replacement on Safari and Firefox. This version adds support for background blur and background replacement on Safari and Firefox. This provides feature consistency across all major browsers and devices, addressing customer requests for uniform background effects support across platforms. To check for the availability of required browser APIs, the SDK uses an inline web worker. This inline web worker may trigger Content Security Policy (CSP) violations in applications that enforce a strict CSP — specifically, those that do not include blob: and data: in the worker-src or child-src directives. For more information, see this documentation.

• Added support for Live Captions Translation. This version adds support for Live Captions Translation, which provides real-time subtitle translation during video calls. Each participant can independently select their preferred translation language. This feature supports the full AWS Translate language set. This is a Private Beta feature—to enable Live Captions Translation for your project, contact us. For more information about Live Captions, see this documentation.

Fixed

• This version fixes a timing issue where setting a media processor connector immediately after subscriber creation could fail. The SDK now waits for the stream to be available before applying the connector.

• This version fixes an issue where streams failed to subscribe in sessions with both End-to-end Encryption and Single Peer Connection enabled.

• This version fixes an issue with automatic reconnection handling that could cause unnecessary connection resets during network recovery. Reconnections now occur more reliably without interrupting stable peer connections.

• This version fixes a race condition where calling subscribeToVideo(true) immediately after subscriber initialization could fail if the video track had not yet been received.

• This version fixes issues where packet loss was incorrectly calculated and where audio fallback events were not fired in some situations. These fixes were identified during the implementation of the network condition insights feature, as audio fallback events are one of the inputs used to determine network health. Both fixes result in more accurate and reliable audio fallback behavior.